Sources
[What's pAVR?]

Sources

The source package contains the following files, in the compiling order:

• std_util.vhd
  • Type conversion routines ofted used throughout the other source files in this project
  • Basic arithmetic functions
  • Sign and zero-extend functions
  • Vector comparision function
• pavr_util.vhd
  • Bypass Unit access function
  • Interrupt arbitrer function
• pavr_constants.vhd
  • Constants needed by pAVR
  • When costumizing pAVR, look and modify (seek-and-destroy) here.
• pavr_data_mem.vhd
• pavr_alu.vhd
• pavr_register_file.vhd
• pavr_io_file.vhd
• pavr_control.vhd
  • pAVR pipeline (pAVR kernel)

Test sources

The test sources in this package implement all the tests presented above.
The test source package contains the following files:

• test_pavr_alu.vhd
  Tests the ALU.
• test_pavr_control_interrupts.vhd
  This test is yet to be done.
• test_std_util.vhd
  Tests the utilities defined in `std_util.vhd'.
• test_pavr_data_mem.vhd
  Tests the Data Memory.
• test_pavr_register_file.vhd
  Tests the Register File.
• test_pavr_io_file.vhd
  Tests the IO File.
• test_pavr_constants.vhd
  Defines constants needed by the main test entity.
• test_pavr_util.vhd
  Defines utilities needed by the main test entity.
• test_pavr_pm.vhd
  Defines the Program Memory that is needed by the main test entity.
• test_pavr.vhd
  Defines the main test entity.
  Tests pAVR as a whole.

Conventions used when writting the VHDL sources

The terminology used reflects the data flow.
For example, `pavr_s4_s6_rfwr_addr1' is assigned in s3 (by the instruction decoder), shifts into `pavr_s5_s6_rfwr_addr1', that finally shifts into `pavr_s6_rfwr_addr1' (terminal register). Only this one carries information actually used by hardware resource managers. This particualr one signalizes an access request to the Register File write port manager.

Process splitting strategy:

• requests to hardware resources are managed by dedicated processes, one VHDL process per hardware resource.
• a main asynchronous process (instruction decoder) computes values that initialize the pipeline in s3.
• a main synchronous process assings new values to pipeline registers.

Todo:

Replace `next_...' signals family with a (pretty wide) state decoder.

Licensing

Please read the licensing terms.

---